Mine trap door



Dec. 28; 1943.

M. C. HALL MINE TRAP DOOR Inventor Filed Feb. 4, 1942 2 Sheets-Sheet 1 Dec. 28, 1943; M. c. HALL I MINE TRAP DOOR 2 Sheets-Sheet 2 Filed Feb. 4, 1942 M n A w w ///Y///K//// N\ lrwentar M MQ Patented Dec. 23, 194-3 UNIT STATES MINE TRAP DQGR Mount Clinie Hall, Weeksbury, Ky., assignor of one-half to William Hale, Drift, Ky.

Application February 4, 1942, Serial No. 429,570

(Cl. 16S1) 1 Claim.

This invention appertains to new and useful improvements in trap doors for coal mines and the like, the principal object of the present invention is to provide a trap door which will remain closed at all times, but can easily open when pushed against by a mine car or other ve-- hicle.

Another important object of the invention is to provide a door of the character stated which will be positive acting, durable and not susceptible to the ready development of defects.

These and other important objects and advantages of the invention will become apparent to the reader of the following description.

In the drawings:

Figure 1 represents a side elevational view of the door structure.

Figure 2 is a top plan view.

Figure 3 is a vertical sectional view taken substantially on the line 3-3 of Figure 1.

Figure 4 is an enlarged fragmentary horizontal sectional View taken substantially on the line lt of Figure 1.

Referring to the drawings wherein like numerals designate like parts, it can be seen that numerals 5, 5 denote hollow pillars at the upper end of each of which is mounted a pulley (5.

Bridging the upper ends of the pillars 5, 5 is a beam 1 which has a vertically disposed opening 8 at its intermediate portion for slidably receiving a plunger 9, which at its upper end is attached to the free end of a strip spring [9, the remaining end of the spring being anchored as at H to the top of the beam It Numeral i2 denotes a base beam bridging the lower ends of the pillars 5 and adjacent the ends of this beam I2 are sockets containing bearings [3 for receiving the lower ends of shafts Hi, the upper ends of which are journaled through the end portions of the upper beam 1 and have their uppermost end portions transversely bored to receive end portions of substantially horizontally disposed rods it, the inner ends of which are provided with eyes it while the outer ends are threaded and equipped with nuts ii to prevent displacement from the shafts Hi.

A cable or the like l8 extends from one eye 16 longitudinally of the beam 1, through guides l9, 2!] to pass over the most distant pulley 6 and eX- tend downwardly in the corresponding pillar 5 where it is attached to a weight 2i. These weights serve to hold doors 22, 222 closed, it being observed from the drawings that these doors 22, 22 are well reinforced, the upper and lower ends being reinforced by straps 23, 2 3, riveted or otherwise secured to the doors. It will be observed that each of these straps 23 is bent in a U-form, its bight portion embracing the corresponding portion of the shaft It. This embracement is sufiicient to hold the door rigidly secured to the shaft and, of course, supplemental fastening means may be used if found necessary. Reinforcing or wear-resisting plates 25 are secured to the intermediate portions of the doors 22, 22 and below these plates 25 are buffer springs 26, these springs being located on each side of each door.

Overlapping strips of flexible material 2'! are provided at the opposed free edges of the doors 22, 22 as is apparent in Figure 1. It is also apparent that the guide 29 limits the rise of the spring It).

At this point consideration should be given to the detent 39 which is secured to the lower end of the plunger 9. This detent 30 is a block having an inverted V-cut 3| at its intermediate bottom portion to receive a correspondingly formed portion of each of the doors 22, 22, it being observable in Figure 3 that the remaining portions of the block 3?) outwardly toward the end thereof slope upwardly as at 32 to facilitate the doors closing and receding into the v-cut 3i assisted by the yieldability of the spring it.

A small hand opening or openings for the purposes denoted by the numeral 33 are formed in the doors 22, 22. (See Figure 1.)

While the foregoing specification sets forth the invention in specific terms, it is to be understood that numerous changes in the shape, size and materials may be resorted to without departing from the spirit and scope of the invention as claimed hereinafter.

Having described the invention, what is claimed as new is:

Door closing apparatus for use in closing a door in a frame having horizontal top and bottom bridge members and a hollow pillar at one side of the frame, said apparatus comprising a rotatable post extending from the bottom member upwardly through the top member at the side of the frame opposite said hollow pillar, means to fix a door to said post to extend from one side thereof for swinging into closed position in the frame under rotation of said post in one direc tion, a rod fixed at one end in said post above the top member and extending laterally from the post and on the same side thereof as said door in a common plane with the door for swinging movement to rotate the post in said one direction, a pulley on said top member vertically aligned with the hollow pillar, a cable extending from the other end of said rod over said pulley and into said pillar, a weight on said cable inside said pillar for causing a pull on said cable, and an apertured cable guide upstanding from said top member adjacent to and outside the arc of swinging movement of said other end of the rod and ofiset laterally of the rod when the door is closed to direct the pull of the cable angularly against said rod and thereby maintain the door closed.

MOUNT CLINIE HALL. 

